Re: power management problems

[Ritesh Raj Sarraf <rrs@researchut.com>]

Bob Proulx wrote:

>> maybe it would be a goog look, to see how much power does your laptop
>> need. on my thinkpad i can look at:
>> /proc/acpi/battery/...
> 
> cat /proc/acpi/battery/*/state
> cat /proc/acpi/battery/*/info
> 

Here's it again:

rrs@learner:~$ cat /proc/acpi/battery/BAT0/state
present:                 yes
capacity state:          ok
charging state:          charging
present rate:            619 mA
remaining capacity:      286 mAh
present voltage:         12590 mV
rrs@learner:~$ cat /proc/acpi/battery/BAT0/info
present:                 yes
design capacity:         4800 mAh
last full capacity:      1003 mAh
battery technology:      rechargeable
design voltage:          11100 mV
design capacity warning: 480 mAh
design capacity low:     145 mAh
capacity granularity 1:  48 mAh
capacity granularity 2:  48 mAh
model number:            DELL YF0806
serial number:           2004
battery type:            LION
OEM info:                SMP

>> and it tells me, how many milliwatts are drawn from the laptop.
>> And Capacity/Milliwatts = Time Your Laptop Will Work
>> 
>> And you are sure, the lifetime is 10minutes? not the display from your
>> battery?
> 
> This is a very good question.  It is not uncommon for the acpi to
> report buggy values.  This might simply be a reporting problem.  How
> long does your laptop actually run before the battery drops off?
>

AFAIU, 5-10 minutes. I noticed is that when on battery, the battery monitor
quickly starts draining from full to half. Once it is half, all of a sudden
it goes to like 5% remaining and I get a warning. And then my machine tries
to hibernate.
If hibernate is disabled, it will wait for another minute and then just
power off.

> On the other hand if your laptop actually does stop running after 5-10
> minutes then I have to wonder if it is not a different problem
> entirely?  Such as are the cooling fans running?  If it simply dies
> quickly then perhaps the battery is fine but that it is overheating?
> In that case 5-10 minutes may be about right for it to generate a lot
> of heat and fail due to over-temperature.  I have heard various
> reports from people of machines that overheat when running Linux due
> either higher cpu utilization or broken acpi fan controls.

I doubt if temperature is really the problem. The cpufreq modules have been
working properly for long.

This laptop used to work properly sometime back. It used to give me an
average battery backup. As Jean had pointed out a change
(speedstep-centrino), I think something that I changed has caused the
problem.

The only other major pm change I can think of is powersaved. I'm removing it
now and will retry with the native klaptopdaemon and see if that helps.

Ritesh
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